An efficient synthetic route to muurolane type sesquiterpenes starting from (R)-carvone, employing allylic diazene rearrangement and the ring closing methesis (RCM) reaction as key steps, is described. The first a...An efficient synthetic route to muurolane type sesquiterpenes starting from (R)-carvone, employing allylic diazene rearrangement and the ring closing methesis (RCM) reaction as key steps, is described. The first asymmetric total synthesis of (-)-10α- hydroxy-4-muurolen-3-one 11 and (-)-10β-hydroxy-4-muurolen-3-one C was accomplished. Through the total synthesis, the absolute configurations of the natural products A, B and C were established.展开更多
Starting from the oxygenated piperidine building block 20,two synthetic approaches to new building blocks (8R,8aS)-and (8R,8aR)-8-hydroxy-5-indolizidinones 19a/19b and 15a/15b have been developed,respectively. The fir...Starting from the oxygenated piperidine building block 20,two synthetic approaches to new building blocks (8R,8aS)-and (8R,8aR)-8-hydroxy-5-indolizidinones 19a/19b and 15a/15b have been developed,respectively. The first one is based on the trans-diastereoselective reductive alkylation (dr = 93:7),followed by a four-step procedure; and the second one called for the RCM reaction on the N,O-acetal derived from a vinylation,which was followed by a pyrrole formation,and a stereocontrolled cis-selective (dr = 91:9) catalytic hydrogenation. Reduction of the diastereomer 15a produced (8R,8aR)-8-indolizidinol (18).展开更多
基金the financial supports from the National Natural Science Foundation of China (No.20272021).
文摘An efficient synthetic route to muurolane type sesquiterpenes starting from (R)-carvone, employing allylic diazene rearrangement and the ring closing methesis (RCM) reaction as key steps, is described. The first asymmetric total synthesis of (-)-10α- hydroxy-4-muurolen-3-one 11 and (-)-10β-hydroxy-4-muurolen-3-one C was accomplished. Through the total synthesis, the absolute configurations of the natural products A, B and C were established.
基金the NSF of China (20672089, 20832005)the NFFTBS (J1030415)the National Basic Research Program of China (973 Program, 2010CB833200)
文摘Starting from the oxygenated piperidine building block 20,two synthetic approaches to new building blocks (8R,8aS)-and (8R,8aR)-8-hydroxy-5-indolizidinones 19a/19b and 15a/15b have been developed,respectively. The first one is based on the trans-diastereoselective reductive alkylation (dr = 93:7),followed by a four-step procedure; and the second one called for the RCM reaction on the N,O-acetal derived from a vinylation,which was followed by a pyrrole formation,and a stereocontrolled cis-selective (dr = 91:9) catalytic hydrogenation. Reduction of the diastereomer 15a produced (8R,8aR)-8-indolizidinol (18).