Enantiopure 2-sulfinylbuta-1,3-dienes in Diels–Alder cycloadditions: a stereoselective approach to an azasteroidal skeleton
摘要:
The synthesis of enantiopure 4-[1-(alkylsulfinyl)vinyl]-1,2-dihydronaphthalenes and their Diels-Alder reactions are described. Cycloadditions with N-phenylmaleimide occur under thermal conditions, very slowly but with notable stereoselection, giving in each case just one of the two endo adducts in high yield. The obtained 16-azasteroid derivatives undergo chiral auxiliary removal in the presence of TMSI. (C) 2001 Published by Elsevier Science Ltd.
Enantiopure 2-sulfinylbuta-1,3-dienes in Diels–Alder cycloadditions: a stereoselective approach to an azasteroidal skeleton
摘要:
The synthesis of enantiopure 4-[1-(alkylsulfinyl)vinyl]-1,2-dihydronaphthalenes and their Diels-Alder reactions are described. Cycloadditions with N-phenylmaleimide occur under thermal conditions, very slowly but with notable stereoselection, giving in each case just one of the two endo adducts in high yield. The obtained 16-azasteroid derivatives undergo chiral auxiliary removal in the presence of TMSI. (C) 2001 Published by Elsevier Science Ltd.