Photochemistry of structural analogues of previtamin D3:: Generality of the wavelength-dependent triene photocyclization

被引:9
作者
Dauben, WG [1 ]
Zhou, BL [1 ]
Lam, JYL [1 ]
机构
[1] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA
关键词
D O I
10.1021/jo9622183
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
Two structural previtamin Da analogues (R = H, CH3) cyclized photochemically with a 1.4-1.8-fold increase in quantum yields over a 3-nm change in excitation wavelength. The sudden increase in quantum yields is due to the participation and mixing of both 2A and 1B excited states. At lambda less than or equal to 306 nm, the 1B state is initially excited and then (a) partitions between isomerization to the corresponding trans triene isomers, (b) decays to the 2A state to give the corresponding cyclohexadienes, and (c) decays to the ground state. At lambda greater than or equal to 309 nm, the 2A state is directly excited to give the corresponding cyclohexadienes and the relaxation path from 1B state to the ground state or isomerization in the 1B state is diminished.
引用
收藏
页码:9005 / 9008
页数:4
相关论文
共 31 条
[1]   RADIATIONLESS DECAY OF 1,3,5,7-OCTATETRAENE [J].
ACKERMAN, JR ;
KOHLER, BE ;
HUPPERT, D ;
RENTZEPIS, PM .
JOURNAL OF CHEMICAL PHYSICS, 1982, 77 (08) :3967-3973
[2]   GEOMETRIC EFFECTS IN THE EXCITED-STATES OF CONJUGATED TRIENES [J].
ANDREWS, JR ;
HUDSON, BS .
CHEMICAL PHYSICS LETTERS, 1979, 60 (03) :380-384
[3]  
[Anonymous], ORGANIC PHOTOCHEMIST
[4]   CONVENIENT SYNTHESIS OF 1ALPHA-HYDROXY-VITAMIN-D3 [J].
BARTON, DHR ;
HESSE, RH ;
PECHET, MM ;
RIZZARDO, E .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1973, 95 (08) :2748-2749
[5]   A NEW MECHANISTIC SCENARIO FOR THE PHOTOCHEMICAL TRANSFORMATION OF ERGOSTEROL - AN MC-SCF AND MM-VB STUDY [J].
BERNARDI, F ;
OLIVUCCI, M ;
RAGAZOS, IN ;
ROBB, MA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1992, 114 (21) :8211-8220
[6]  
BERNARDI F, 1993, ISRAEL J CHEM, V33, P265
[7]   LOWEST ENERGY EXCITED SINGLET-STATES OF ISOMERS OF ALKYL SUBSTITUTED HEXATRIENES [J].
BUMA, WJ ;
KOHLER, BE ;
SONG, K .
JOURNAL OF CHEMICAL PHYSICS, 1991, 94 (07) :4691-4698
[8]   WHAT HAPPENS DURING THE PICOSECOND LIFETIME OF 2A(1) CYCLOHEXA-1,3-DIENE - A CAS-SCF STUDY OF THE CYCLOHEXADIENE HEXATRIENE PHOTOCHEMICAL INTERCONVERSION [J].
CELANI, P ;
OTTANI, S ;
OLIVUCCI, M ;
BERNARDI, F ;
ROBB, MA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1994, 116 (22) :10141-10151
[9]  
COURTIN JML, 1987, RECL TRAV CHIM PAY B, V106, P112
[10]   WAVELENGTH-CONTROLLED PRODUCTION OF PRE-VITAMIN D3 [J].
DAUBEN, WG ;
PHILLIPS, RB .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1982, 104 (01) :355-356