Angucyclinones Related to Ochromycinone. IV. The Structures and Reactions of Unusual Diels-Alder Adducts Formed from Maleic Anhydride and Racemic 5,5-Dimethyl-3-vinylcyclohex-2-en-1-ol
作者:Craig Brinkworth、Tomas Rozek、John H. Bowie、Brian W. Skelton、Allan H. White
DOI:10.1071/ch00034
日期:——
The Diels–Alder reaction between maleic anhydride and racemic5,5-dimethyl-3-vinylcyclohex-2-en-1-ol gives two racemic diastereomers, themajor product(2a,S,3R,8aS,8bR)-7,7-dimethyl-2-oxo-2a,3,4,6,7,8,8a,8b-octahydro-2H-benzo[cd]isobenzofuran-3-carboxylicacid (63% yield), and the minor product(2aR,3S,8aS,8bS)-7,7-dimethyl-2-oxo-2a,3,4,6,7,8,8a,8b-octahydro-2H-benzo[cd]isobenzofuran-3-carboxylicacid (9%)
马来酸酐与外消旋5,5-二甲基-3-乙烯基环己基环己基-2-烯-1-醇的Diels-Alder反应产生两种外消旋非对映异构体,主要产物(2a,S,3R,8aS,8bR)-7,7-二甲基-2-oxo-2a,3,4,6,7,8,8a,8b-八氢-2H-苯并[cd]异苯并呋喃-3-羧酸(产率63%)和次要产物(2aR,3S,8aS ,8bS)-7,7-二甲基-2-氧代-2a,3,4,6,7,8,8a,8b-八氢-2H-苯并[cd]异苯并呋喃-3-羧酸 (9%)。主要产物的环氧化得到外消旋 (1aS,3R,3aS,5aR,8aS,8bR)-7,7-dimethyl-4oxoperhydro-benzo[cd]oxireno[2,3-e]isobenzofuran-3-carboxyacid,产率为 81% , 而环氧化物环的开环得到 58% 的 transdiol(2aS,3R,5S,5aR,8aR