In my family, we never pronounced Brötchen with a long ö, but rather a sound reminiscent of a diphthong oi or öi. In any case, Brötchen with a long ö sounds totally alien and unfamiliar to me.
But what is the standard German pronunciation? Is there any dialectal area (Rhineland?) where such a pronunciation is common?
Wiktionary normally includes non-standard but common pronunciations, but in this case they only listed one possible pronunciation. It's also the only one I've heard. The standard way being [ˈbʀøːtçən].
I tried checking forvo for a recording from a person from Rhineland without success, but it's worth noting people from different regions all pronounced it pretty much the same way.
According to Duden Volume 6 – Aussprachewörterbuch, the standard pronunciation of Brötchen is [ˈbrøːtçən].
A sound sample can be found here.
I have never heard /'bröitchen/. The normal vowel is a long or half-long ö. Maybe there is a pronunciation with öi, perhaps in Siebenbürgen or Jiddisch or perhaps with the Amish in USA.
