Transannular anti-Michael addition: formation of 4H-pyrazolo[5,1-c]thiazines
摘要:
The reaction of 2-(diphenylmethylene)thietan-3-one (2) with 1,2,4,5-tetrazines (3a-c) in KOH/MeOH/THF gives 4H-pyrazolo[5,1-c]thiazines (7a-c). This novel condensation reaction proceeds via the intermediacy of an 8-(diphenylmethylene)-2H-1,4,5-thiadiazocin-7(8 H) -one (5), which undergoes a multi-step rearrangement including a rare anti-Michael addition. (c) 2006 Elsevier Ltd. All rights reserved.
Transannular anti-Michael addition: formation of 4H-pyrazolo[5,1-c]thiazines
摘要:
The reaction of 2-(diphenylmethylene)thietan-3-one (2) with 1,2,4,5-tetrazines (3a-c) in KOH/MeOH/THF gives 4H-pyrazolo[5,1-c]thiazines (7a-c). This novel condensation reaction proceeds via the intermediacy of an 8-(diphenylmethylene)-2H-1,4,5-thiadiazocin-7(8 H) -one (5), which undergoes a multi-step rearrangement including a rare anti-Michael addition. (c) 2006 Elsevier Ltd. All rights reserved.