9196
R. Grigg et al. / Tetrahedron 57 ꢀ2001) 9187±9197
bis-dienes 60.2 g) and N-methylmaleimide 63 equiv.) were
mixed in dry THF 610 ml) in a Schlenk tube. The solution
was stirred at 1108C for 18 h, then cooled, vented and the
solvent evaporated under reduced pressure. The residue was
puri®ed by column chromatography. The low melting
products were dif®cult to obtain free of small amounts of
water of crystallisation.
1:1 mixture of 36a and 36b 681%) as a colourless amor-
phous powder, mp 62±648C. 6Found: C, 64.3; H, 6.9; N, 5.6.
C27H34N2O7´0.25H2O requires: C, 64.5; H, 6.85; N, 5.55%);
HRMS 6found): 521.2285. C27H34N2O7Na requires
521.2264; dH 1.65 6s, 6H, 2£CH3Cv), 1.67 6s, 3H,
CH3Cv), 1.78 6m, 3H, CH3±Cv), 2.16 and 2.17 62£s, 2£
3H, 2£CH3CO), 2.23±2.8 6m, 20H, CH and CH2), 2.89 6s,
3H, NCH3), 2.94 6s, 9H, 3£NCH3), 2.99 6m, 12H, CH and
CH2) and 3.65 and 3.69 62£s, 2£3H, 2£OCH3); m/z 6%): 499
6M111, 100), 498 6M1, 7), 276 630), 192 631) and 57 636).
3.2.1. 2--2,6-Dimethyl-1,3-dioxo-2,3,3a,4,7,7a-hexahydro-
1H-isoindol-5-ylmethyl)-malonic acid dimethyl ester
-34). Column chromatography eluting with 19:1 v/v
dichloromethane±ethyl acetate afforded the product 679%)
as an amorphous colourless solid, mp 73±748C. 6Found: C,
59.2; H, 6.75; N, 4.3. C16H21NO6 requires: C, 59.45; H,
6.55; N, 4.35%); dH 1.67 6s, 3H, Me), 2.25 and 2.45 62£
2H, 2£ vCCH2), 2.58 6dd, 1H, J6.5 and 14.1 Hz, 1H of
exocyclic CH2), 2.686dd, 1H, J8.9 and 14.1 Hz, 1H of
exocyclic CH2), 2.95 6s, 3H, NMe), 3.05 6m, 2H, ring
junction protons), 3.55 6dd, 1H, J6.5 and 8.9 Hz,
COCHCO) and 3.67 and 3.70 62£s, 2£3H, OMe); m/z
6%): 323 6M1, 8), 231 6100), 192 649), 107 654) and 91 683).
3.2.4. 2,2-Dimethyl-5,5-bis--2,6-dimethyl-1,3-dioxo-2,3,
3a,4,7,7a-hexahydro-1H-isoindol-5-ylmethyl)-[1,3]-di-
oxane-4,6-dione -37a,b). Column chromatography eluting
with 3:16:1 v/v/v petroleum ether±ether±methanol afforded
a 1:1 mixture of 37a and 37b 664%) as a colourless amor-
phous powder, mp 89±908C. 6Found: C, 62.45; H, 6.35; N,
4.9. C28H34N2O8´0.75H2O requires: C, 62.3; H, 6.6; N,
5.2%); dH 1.57 6s, 12H, 4£Me), 1.68 6s, 3H, CH3±Cv),
1.71 6s, 9H, 3£CH3±Cv), 2.1±2.16 6m, 8H, CH and
CH2), 2.42±2.59 6m, 12H, CH and CH2), 2.93 6s, 12H, 4£
NCH3), 2.97 6m, 8H, CH and CH2) and 3.12±3.18 6m, 4H,
CH and CH2); m/z 6%): 424 6M126CH3)2CCO2, 2), 232 64),
182 665), 113 656), 55 682) and 41 6100).
3.2.2. 3,3-Bis--2,6-dimethyl-1,3-dioxo-2,3,3a,4,7,7a-hexa-
hydro-1H-isoindol-5-ylmethyl)-pentane-2,4-dione -35a,b).
Column chromatography eluting with 3:16:1 v/v/v petro-
leum ether±ether±methanol afforded a 1:1 mixture of 35a
and 35b 656%) as a colourless amorphous powder, mp
64±658C. 6Found: C, 66.05; H, 7.05; N, 5.8.
C27H34N2O6´0.5H2O requires: C, 66.0; H, 7.15; N, 5.7%);
HRMS 6found): 505.2315. C27H34N2O6Na requires
505.2296; dH 1.7, 1.74, 1.92 and 1.98 64£s, 4£3H, 4£
CH3Cv), 2.196s, 3H, CH3CO), 2.21 6s, 9H, 3£CH3CO),
2.23±2.49 6m, 16H, CH and CH2), 2.83±2.89 6m, 4H, CH
and CH2), 2.93 6s, 9H, 3£NCH3), 2.94 6s, 3H, NCH3) and
2.99±3.06 6m, 12H, CH and CH2); m/z 6%): 483 6M111,
12), 439 65), 292 614), 192 634), 83 640), 73 670) and 69
6100).
3.2.5.
Bis--2,6-dimethyl-1,3-dioxo-2,3,3a,4,7,7a-hexa-
hydro-1H-isoindol-5-ylmethyl)-bis--phenylsulpfonyl)-
methane -38a,b). Column chromatography eluting with
3:16:1 v/v/v petroleum ether±ether±methanol afforded a
1:1 mixture of 38a and 38b 683%) as a colourless amor-
phous powder, mp 204±2058C. 6Found: C, 59.5; H, 5.55; N,
3.8; S, 9.6. C35H38N2O8S2´0.5H2O requires: C, 61.15; H,
5.65; N, 4.05; S, 9.3%); HRMS 6found): 701.1954.
C35H38N2O8S2Na requires 701.1967; dH 1.62 6s, 6H, 2£
Me), 1.75 6s, 6H, 2£Me), 1.85 6m, 2H, CH and CH2),
2.0±2.3 6m, 6H, CH and CH2), 2.4±2.5 6m, 4H, CH and
CH2), 2.7±2.85 6m, 4H, CH and CH2), 2.92 and 2.93 62£s,
3.2.3. 2,2-Bis--2,6-dimethyl-1,3-dioxo-2,3,3a,4,7,7a,hexa-
hydro-1H-isoindol-5-ylmethyl)-3-oxo-butyric acid methyl
ester -36a,b). Column chromatography eluting with
3:16:1 v/v/v petroleum ether±ether±methanol afforded a