Question

what is each step doing.. be descriptive

RPH Ser B1
Step 1

Step 2

Step 3

Answer 1

The provided reaction proceeds through a seven-membered ring formation which adds to the stability of the intermediate.

In Step I, the oxygen in -OH of Ser B1 attacks the electrophilic carbonyl carbon. In this step, as the H in -OH of Ser B1 is hydrogen-bonded to a water molecule and as the entire system is participating in a seven-membered ring, hydrogen exchange takes place between the -OH and water molecule. the same case is with the $-NH_{2}$ of Ser B1 in step 1. The mechanism is shown in detail below

Meomuhile hene the-veis via H-bonding interactions ehongein beingstabilize b1 two gtou R Seven membercd omaion sen B ater melecule -bonding ier cusay ie ater mlecule This moo 4 an ve +ve on o mttable t2 -# R R NH #2 his,the im waten molecule becomen te ahangect. So, e Now athe -ve im O to ton R-Ngouoe a the R-H which abstac t the seven membered nin out otom frtem its away O U

R R here the R'-NH abstracts a -R-H proton from the seven mem ring system -1> 7----- H2 H. R-NH R-MHZ +o H Ho R-NH the OH- at last abstracts proton from -NH3+ to form water again