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NHTf
49
TIPSO
OPiv
NHTf
CHO
OTIPS
Zn
+
2
Ti(O i Pr) 4
48
47
OH
TESO
PPh 3 I
TIPSO
OPiv
( ) 4
O
OTIPS
50
51
TBDMSO
O
OHC
TBDMSO
52
O
O
OHC
O
O
O
MgBr
53
C 11 H 23
OH
OH
54
O
O
C 12 H 25
( ) 5
O
OH
HO
O
trans-THF
(4 R ,12 R ,15 S ,16 S ,19 R ,20 R ,34 S )- Muricatetrocin
(proposed structure for Muricatetrocin B )
OH
TBDMSO
O
TIPSO
( ) 4
OPiv
OHC
( ) 5
O
OTIPS
O
55
56
OH
OH
O
54
C 12 H 25
( ) 5
O
OH
HO
O
cis-THF
(4 R ,12 S ,15 S ,16 S ,19 R ,20 R ,34 S )- Muricatetrocin
( Muricatetrocin A )
Scheme 10-12. Total synthesis of muricatetrocin A and B by Baurle et al.
A similar disconnection strategy was adopted by Dixon et al. in the United Kingdom
in the synthesis of muricatetrocin C. 39,40 The retro-synthesis disconnected the
target into three parts, aldehyde 59, terminal alkyne precursor 60, and vinyl iodide
64 (Scheme 10-13). The THF-containing aldehyde 59 was prepared from com-
pound 58, an O-C rearranged product from 57. Compound 60 was synthesized
from dimethyl L-tartrate. Compound 64 was prepared with a hetero Diels-Alder
reaction. The terminal acetylene lithium derived from 60 was added to aldehyde
59, which gave a major product with erythro configuration. This erythro product
was converted into the threo product by alcohol oxidation and ketone reduction
 
 
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