Page 1201 - Advanced Organic Chemistry Part B - Reactions & Synthesis

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Scheme 13.6. Retrosynthetic Analysis of Juvabione with Disconnection to the Terpene
Limonene
SECTION 13.2
R Illustrative Syntheses
CO 2 CH 3
O
H 2 C
CH
3 (CH 3 ) 2 CHCH 2 CX +
H
H
O CH CH
CH 3 3 3
limonene (R = CH )
3
perillaldehyde (R = CH O)
Scheme 13.7. Juvabione Synthesis: B. A. Pawson, H.-C. Cheung, S. Gurbaxani, and
G. Saucy a
B
CH A CH 3 1) C 7 H SO Cl CH 3
2
7
3 2) NaCN
1) R BH CH CH
2 3 3
H C C 3) (CH ) CHCH Li H
2
3 2
2
2
H 2) H 2 O , HOCH 2 H 4) H , H O CH 3 O CH 3
+
C OH H 2
H 3
(diastereomers 1) O , sens, hν
2
separated here) C 2) I –
3) Cr(VI)
D
CH O
1) Ag O
2
2) CH N
erythro-juvabione 2 2 CH 3
O H
CH 3
CH 3
a. B. A. Pawson, H.-C. Cheung, S. Gurbaxani, and G. Saucy, J. Am. Chem. Soc., 92, 336 (1970).
Scheme 13.8. Juvabione Synthesis: E. Negishi, M. Sabanski, J. J. Katz, and H. C. Brown a
A B
CH O
CO 2 CH 3
1) NH 2 OH + RBCH 2 CH(CH 3 ) 2 1) CO mixture of
2) Ac 2 O 2) H 2 O 2 , NaOH juvabione and
H 2 C C H 2 C C H
H 3) KOH H epijuvabione
CH 3
CH 3 4) CH 2 N 2 CH 3
R = –CCH(CH 3 ) 2 (thexyl)
CH 3
a. E. Negishi, M. Sabanski, J. J. Katz, and H. C. Brown, Tetrahedron, 32, 925 (1976).
Scheme 13.9. Juvabione Synthesis: A. A. Carveiro and I. G. P. Viera a
CH O B
A
CO 2 CH 3 1) Ca(OCl) 2 CO 2 CH 3
1) AgO
CH 3 –78°C CH 3
CH 3
H 2) CH 2 N 2 2) (CH ) CHCH O
CH 2 H 3 2 H
Zn
CH 2 CH 3 O CH 2
3) PCC
RhCl (PPh 3 ) 3
D
H 2
mixture of juvabione
and epijuvabione
a. A. A. Carveiro and L. G. P. Viera, J. Braz. Chem. Soc., 3, 124 (1992).