[Chudasama]

just had 2 quick questions with regards to the attached mechanism...

1) NMR showed there to be a predominance of the trans-isomer but i can't figure out why, only thing i can think of is sterics but i'm sure there's more to it

2) Are the initial steps in my mechanism correct?

if someone could push me in the right direction i would really apprecicate it

thanks

[movies]

Your mechanism looks pretty good, you abbreviated a couple of steps, but that's okay.

As for the selectivity, sterics is part of it, but also think about the arrangement of the groups in the product.  Do you think it's the more thermodynamically stable isomer?

[Chudasama]

...is the trans-isomer more stable as one of its chair conformations has both groups equatorial, therefore minimising unstable 1,3-diaxial steric interactions...??