Stereoselectivity in the photoinduced electron transfer (PET) promoted intramolecular cyclisations of 1-alkenyl-2-silyl-piperidines and -pyrrolidines: rapid construction of 1-azabicyclo[m.n.0]alkanes and stereoselective synthesis of (±)-isoretronecanol and (±)-epilupinine
摘要:
PET promoted cyclisations of 1-alkenyl-2-silyl-pyrrolidines and -piperidines 9a-d to 1-aza-bicyclo[m.n.0]alkanes have been found to be stereoselective. The five-membered ring formation gives predominantly cis products while six-membered rings are trans. Application of such cyclisations to the synthesis of (+/-)-isoretronecanol 22a, (+/-)-epilupinine 29 and related alkaloids has been demonstrated.
Stereoselectivity in the photoinduced electron transfer (PET) promoted intramolecular cyclisations of 1-alkenyl-2-silyl-piperidines and -pyrrolidines: rapid construction of 1-azabicyclo[m.n.0]alkanes and stereoselective synthesis of (±)-isoretronecanol and (±)-epilupinine
摘要:
PET promoted cyclisations of 1-alkenyl-2-silyl-pyrrolidines and -piperidines 9a-d to 1-aza-bicyclo[m.n.0]alkanes have been found to be stereoselective. The five-membered ring formation gives predominantly cis products while six-membered rings are trans. Application of such cyclisations to the synthesis of (+/-)-isoretronecanol 22a, (+/-)-epilupinine 29 and related alkaloids has been demonstrated.
Synthesis and structure–activity relationships of a new class of selective EP 3 receptor agonist, 13,14-didehydro-16-phenoxy analogues of prostaglandin E 1
A series of 13,14-didehydro-16-phenoxy analogues of prostaglandin E1 was synthesized and their agonistic activity on EP receptor subtypes was evaluated. 13,14-Didehydro-16-phenoxy-1-decarboxy analogues, 7e and 7f, display highly selective activity on the EP3 receptor subtype, thus, their utility as a selective anti-ulcer agent can be expected.