A Route to Carbasugar Analogues - Jonathan Clayden - The ...

Chapter 1: Introduction
A scheme summarising this reactivity is presented below.
87
Mn(CO) 3
+
RM
LiAlH 4
or MeLi
R
E +
R
88
Mn(CO) 3 R = H, Me
NOPF 6
DCM
i) NuM
ii) O 2
"Reactive"
nucleophiles
R
i) NuM
ii) Me 3 NO
R
Mn(CO) 2 NO +
Nu
90 ±89
Scheme 1.25 – synthetic summary of Mn(CO) chemistry
3
Due to their more reactive nature, the regioselectivity of addition to these arenes is not
as dependent upon the substrate or nucleophile as Cr(CO) 3 complexes. This is
presumably due to the irreversible nature of the addition.
1.4.2.a Asymmetric synthesis using Mn(CO) 3 complexes
Due to the limitations of the chemistry outlined above, little work has been done
regarding asymmetric additions to these complexes. Miles and co-workers found that
use of chiral oxazolidine enolates as nucleophiles results in diastereoselectivity at the
dearomatised centre. 57
(Scheme 1.26).
This technique was extended to the synthesis of (+)-juvabione
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