TY - JOUR
T1 - Synthesis of (±)-Glaucine and (±)-Neospirodienone via an One-Pot Bischler-Napieralski Reaction and Oxidative Coupling by a Hypervalent Iodine Reagent
AU - Huang, Wei Jan
AU - Singh, Om V.
AU - Chen, Chung Hsiung
AU - Lee, Shoei Sheng
PY - 2004
Y1 - 2004
N2 - Condensation of 3,4-dimethoxybenzeneethanamine (3d) and various benzeneacetic acids, i.e., 4a-e, via a practical and efficient one-pot Bischler-Napieralski reaction, followed by NaBH4 reduction, produced a series of 1-benzyl-1,2,3,4-tetrahydroisoquinolines, i.e., 5a-e, in satisfactory yields (Scheme 3). Oxidative coupling of the N-acyl and N-methyl derivatives 6a-e of the latter with hypervalent iodine ([IPh(CF 3COO)2]) yielded products with two different skeletons (Scheme 4). The major products from N-acyl derivatives 6a-c were (±)-N-acylneospirodienones 2a-c, while the minor was the 3,4-dihydroisoquinoline 7. (±)-Glaucine (1), however, was the major product starting from N-methyl derivative 6e. Possible reaction mechanisms for the formation of these two types of skeleton are proposed (Scheme 5).
AB - Condensation of 3,4-dimethoxybenzeneethanamine (3d) and various benzeneacetic acids, i.e., 4a-e, via a practical and efficient one-pot Bischler-Napieralski reaction, followed by NaBH4 reduction, produced a series of 1-benzyl-1,2,3,4-tetrahydroisoquinolines, i.e., 5a-e, in satisfactory yields (Scheme 3). Oxidative coupling of the N-acyl and N-methyl derivatives 6a-e of the latter with hypervalent iodine ([IPh(CF 3COO)2]) yielded products with two different skeletons (Scheme 4). The major products from N-acyl derivatives 6a-c were (±)-N-acylneospirodienones 2a-c, while the minor was the 3,4-dihydroisoquinoline 7. (±)-Glaucine (1), however, was the major product starting from N-methyl derivative 6e. Possible reaction mechanisms for the formation of these two types of skeleton are proposed (Scheme 5).
UR - http://www.scopus.com/inward/record.url?scp=1342322964&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1342322964&partnerID=8YFLogxK
U2 - 10.1002/hlca.200490005
DO - 10.1002/hlca.200490005
M3 - Article
AN - SCOPUS:1342322964
SN - 0018-019X
VL - 87
SP - 167
EP - 174
JO - Helvetica Chimica Acta
JF - Helvetica Chimica Acta
IS - 1
ER -