Chapter 30 — Retrosynthetic analysis Planning a synthesis by going

Chapter 30 — Retrosynthetic analysis

Planning a synthesis by going in reverse

I can make that! C–C disconnections from familiar reactions

Example: a return to platensimycin

Example: monensin

I can make that! (C–C disconnections 1.)

OHO

OO

OHOH OHO

O O

O O

O

RO

OClaisen

1 32

1 32

1 32

aldol

aldol[Red.]

[Red.]

1,3 - O,O

O OHO O Oaldolα,β

Elim.

I can make that! (C–C disconnections 2.)

R

OHN

1 32

1,3 - N,O

R' R'

R

ONR' R'O

R H

ONH

R' R'

Mannich[Red.]

1,5 - O,OO

O

OR

O

O

ORMichael

HO OH

R R'[Red.]

O O

R R'Michael

O

R

O

R'

1 32

45

1 32 54

Monensin: How on earth?

Monensin: How on earth?

Monensin: How on earth?